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Flow Developments in Smooth Wall Circular Duct Facility<br />
E.-S. Zanoun ∗ , F. Durst † ,C.Egbers ∗ ,L.Jehring ∗ ,andM.Kito ∗<br />
The fully developed turbulent pipe flow represents the state of well-defined flow<br />
that has been the subject of numerous investigations of engineers and scientists interested<br />
in its basic properties and in understanding fully developed turbulence. Recently,<br />
a number of publications 1,2,3,4 resulted out of studies of fully developed turbulent<br />
pipe flows, yielding general conviction that the mean flow properties of this<br />
flow are fully understood. This is not the case, since a controversy discussion regarding<br />
the frictional loss and normalized form of the mean velocity distribution of<br />
fully-developed turbulent pipe flow still exists. For instance, it was pointed out 5 that<br />
many of the assumptions made in deriving the Moody Diagram as an engineering<br />
guide are not correct. The main aim of the present paper is therefore to provide a<br />
good basis for assessing questions regarding turbulent flow development length of the<br />
mean and fluctuating velocities as well as frictional loss along a smooth pipe flow test<br />
section. A new circular duct test rig is therefore setup at the Department of Fluid<br />
<strong>Mechanics</strong> and Aerodynamics (LAS) of BTU Cottbus to investigate the fully developed<br />
turbulent pipe flows at relatively high Reynolds number (Rem). The research<br />
program is designed mainly into two different phases. Phase I covers the application<br />
of some advanced measuring techniques for better understanding and quantitatively<br />
evaluating the mean flow characteristics and turbulence statistics for Rem ≤ 6 × 10 5 .<br />
For the sake of comparison against the most recent pipe flow data from different<br />
experiments, the second phase focuses on extending the Reynolds number range to<br />
Rem ≤ 1.2 × 10 6 . In addition, the results obtained from Phase I and Phase II are<br />
used to validate some recently developed theoretical investigations 6,7,8 .<br />
∗ LAS BTU Cottbus, Siemens-Halske-Ring 14, 03044-Cottbus, Germany.<br />
† LSTM Erlangen, Cauerstr. 4,D-91058 Erlangen, Germany.<br />
1 Barenblatt, J. Fluid Mech. 248, 513 (1993).<br />
2 Zagarola & Smits, J. Fluid Mech. 373, 33 (1998).<br />
3 Wei et al. J. Fluid Mech. 482, 51 (2005).<br />
4 Zanoun et al., HEFAT (2005).<br />
5 Smits, Midwest <strong>Mechanics</strong> Seminar Series (2005-2006).<br />
6 Wosnik et al. J. Fluid Mech., 421, 115(2000).<br />
7 Oberlack, J. Fluid Mech., 299, 51 (2001).<br />
8 Monkewtiz &Nagib, IUTAM (2004).<br />
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